A:   I don't think there is a potential problem with nitrates because the plant was not stressed and the fact that you are harvesting means that the plant is mature and nitrates decrease as the plant matures. The green in the plant I assume is not "new" growth or new shoots. The green in the plant will contain some prussic acid, but usually not at a level that is a problem for cows. However, delayed frost, unseasonably warm temperatures and moisture allow grain sorghum plants to develop new growth after grain harvest. This new green growth, commonly referred to as "suckers", are usually high in toxic prussic acid. If "sucker" growth occurs, cattle should not graze the stubble until at least seven days following a hard freeze.